1. Field of the Invention
The present invention relates to a seatbelt system for restraining and protecting an occupant in a vehicular emergency, and more particularly to improvements in a full-passive type seatbelt system wherein means for driving the webbing is automatically actuated in accordance with the actions of the occupant getting into or out of the vehicle so as to fasten the webbing to the occupant or release the webbing from the occupant.
2. Description of the Prior Art
To secure the safety of the occupant in an accidental collision which would occur to the vehicle, there have heretofore been used seatbelt systems. To further improve the safety of the occupant, there have been proposed the so-called full-passive type seatbelt systems capable of automatically fastening the webbing for restraining or releasing the occupant in accordance with the actions of the occupant getting into or out of the vehicle.
In said full-passive type seatbelt system, the webbing for restraining the occupant is secured at one end thereof to the side surface of a seat for the occupant on the side opposite the door for getting into or out of the vehicle and at the other end thereof to the door, and the portion of the webbing mounted on the door is moved in the longitudinal direction of the vehicle by driving means such as a motor, whereby the space existing between the webbing and the seat for the occupant is expanded or contracted, so that space for the occupant to get into or out of the vehicle is provided when the occupant gets into or out of the vehicle, and the webbing can be reliably fastened to the occupant after the occupant has gotten into the vehicle. Additionally, a switch for detecting the conditions of the door being open and closed is provided in an electric circuit of said motor, whereby, in the case of the door being closed, the webbing is moved toward the rear of the vehicle, i.e. in the direction of the seat to fasten the occupant thereto with the webbing, and, in the case of the door being open, the webbing is moved toward the front of the vehicle to form a space sufficient for the occupant to get into and out of the vehicle between the webbing and the seat.
FIG. 1 shows one example of the full-passive type seatbelt system which has been proposed heretofore. In the drawing, designated at 10 is a vehicle body, 12 a seat for an occupant being disposed on the floor of said vehicle body 10, 14 a webbing retractor solidly secured to the side surface of said seat 12 to one side of the center of the vehicle, 16 a guide rail attachingly provided on the roof side member of the vehicle body 10, 18 a slide plate slidable along said guide rail 16 in the longitudinal direction of the vehicle, 20 a seatbelt of webbing, the inner end 20a of which is wound up into said retractor 14 by its biasing force and the outer end 20b of which is engaged with said slide plate 18, 22 a retractor solidly secured to the roof side member of the vehicle for constantly biasing said slide plate 18 toward the rear of the vehicle through a narrow width webbing 24, and 26 driving means for moving said slide plate 18 in the longitudinal direction of the vehicle by winding up one end of a wire 28, the other end of which is fixed on said slide plate 18. Here, the driving means 26 is adapted to be operated on detecting the action of the occupant getting out of the vehicle. For instance, if the occupant opens the door for getting into or out of the vehicle, this driving means is operated by an opened door detecting signal emitted then. Furthermore, the driving means 26 is adapted to deliver the wire 28 by the action of the occupant in being seated, e.g. by closing the door after he or she is seated. With the above-described full-passive type seatbelt system, in the case of the door being closed, the webbing is moved toward the rear of the vehicle, i.e. in the direction of the occupant's seat, whereby the webbing is fastened to the occupant, and, in the case of the door being open, the webbing is moved toward the front of the vehicle, whereby a space sufficient for the occupant to get into and out of the vehicle is formed between the webbing and the seat for the occupant.
In the above-described conventional full-passive type seatbelt system, the motor or driving means to move the webbing for restraining or releasing the occupant should desirably operate for a period of time necessary for restraining or releasing the occupant by moving the webbing. In connection thereto, the conventional full-passive type seatbelt system has a disadvantage in that the excess operation of the motor beyond the necessary period of time causes the motor to be in trouble by being locked from rotating. The same problem to the motor occurs when the webbing stops moving for some reason during the necessary period of time.